A) phospholipids 11) glycolipids C) cholesterol D) phytostero E) cerebrosides S2) Localized
regions of plasma membranes that contain cholesterol and proteins involved n cell signaling are
known as A) gap junctions B) arterial plaques C) cadherin junctions D) lipid rafs. E)
plasmodesmata. 53) Most cells have a negative plasma membrane potential (Vm) because they
have A) equal concentrations of ions on both sides of the membrane an excess of negatively
charged solute molecules inside the cell. C) an excess of positively charged solute molecules
inside the cell. D) an excess of negatively charged solute molecules outside the cell. E) an excess
of water molecules inside the cell. 54) The Na/K+ ATPase pump actively moves A) 2 Na* in, 3
K out B) 2 Nat out, 3 K* in. C) 3 Na* in 2 K+ out L) 3 Na+ out. 2 K+ in. E) 1 Nat out, I K+ in
55) Which of the following is true for the mechanism of the 2Na /glucose symporter? A) Binding
of 2 Nat to the symporter open to the outside of the cell allows a glucose molecule outside the
cell to bind. B) Binding of Nat and glucose causes the symporter to open to the inside of the cell.
C) Release of 2 Nat ions to the inside of the cells causes release of the glucose molecule, D)
Binding of 2 Na to the symporter on the inside of the cell causes the symporter to open to the
outside of the cell and release of the Nat ions E) All of the above are steps in the mechanism. 56)
Phosphorylation of glucose following its transport into a cell A) targets the glucose for transport
back out of the cell. B) decreases glucose transport into the cell by decreasing its concentration
gradient across the plasma membrane. C) increases glucose transport into the cell by increasing
its concentration gradient across the plasma membrane D) converts glucose into a form that can
more easily be exported from the cell. E) maintains a higher level of glucose outside the cell.
Solution
52. D. Lipid Rafts
This part of the plasma membrane is not very fluid and is thicker compared to the rest of the
membrane.
53. b. An excess of negatively charged solute molecules inside the cell.
Most cells have a negative plasma membrane potential because of an excess of negatively
charged solute molecules inside the cell.
54. D. 3 Na+ out, and 2K+ in.
Sodium-potassium pump, pumps out 3 sodium ions out of the cell and pumps in 2 potassium ions
inside the cell.
regions of plasma membranes that contain cholesterol and proteins involved n cell signaling are
known as A) gap junctions B) arterial plaques C) cadherin junctions D) lipid rafs. E)
plasmodesmata. 53) Most cells have a negative plasma membrane potential (Vm) because they
have A) equal concentrations of ions on both sides of the membrane an excess of negatively
charged solute molecules inside the cell. C) an excess of positively charged solute molecules
inside the cell. D) an excess of negatively charged solute molecules outside the cell. E) an excess
of water molecules inside the cell. 54) The Na/K+ ATPase pump actively moves A) 2 Na* in, 3
K out B) 2 Nat out, 3 K* in. C) 3 Na* in 2 K+ out L) 3 Na+ out. 2 K+ in. E) 1 Nat out, I K+ in
55) Which of the following is true for the mechanism of the 2Na /glucose symporter? A) Binding
of 2 Nat to the symporter open to the outside of the cell allows a glucose molecule outside the
cell to bind. B) Binding of Nat and glucose causes the symporter to open to the inside of the cell.
C) Release of 2 Nat ions to the inside of the cells causes release of the glucose molecule, D)
Binding of 2 Na to the symporter on the inside of the cell causes the symporter to open to the
outside of the cell and release of the Nat ions E) All of the above are steps in the mechanism. 56)
Phosphorylation of glucose following its transport into a cell A) targets the glucose for transport
back out of the cell. B) decreases glucose transport into the cell by decreasing its concentration
gradient across the plasma membrane. C) increases glucose transport into the cell by increasing
its concentration gradient across the plasma membrane D) converts glucose into a form that can
more easily be exported from the cell. E) maintains a higher level of glucose outside the cell.
Solution
52. D. Lipid Rafts
This part of the plasma membrane is not very fluid and is thicker compared to the rest of the
membrane.
53. b. An excess of negatively charged solute molecules inside the cell.
Most cells have a negative plasma membrane potential because of an excess of negatively
charged solute molecules inside the cell.
54. D. 3 Na+ out, and 2K+ in.
Sodium-potassium pump, pumps out 3 sodium ions out of the cell and pumps in 2 potassium ions
inside the cell.
